The present disclosure relates generally to the field of detecting the radiance of objects with a pixel array. More particularly, the present disclosure relates to detecting the radiation emitted from various objects at specific wavelengths in order to determine the temperature of the various objects. This technology can be used in variety of applications including but not limited to thermal imaging, medical imaging, night vision, hyper-spectral imaging, head-up display (HUD) systems and wearable displays, such as, helmet mounted display (HMD) systems, and object detection such as automatic target recognition (ATR).
In the field of infrared (IR) radiation detection, methods of improving detection accuracy at low costs and low processing latency is greatly desired. Some radiation imaging systems use an array of photodiodes or microbolometers to capture radiation emitted from various objects to detect, for example, infrared energy information to be displayed for a user. Conventional single energy detection systems have limited responsivity, meaning the detectors used in these systems are only able to detect a relatively low portion of the incident energy associated with the radiance of an object captured by a given pixel in an pixel photodiode array. Furthermore, they cannot determine the temperature of an object without resorting to object-specific calibration procedures.
For example, certain radiating objects, such as human beings, are only slightly above room temperature and are more easily detected in the long wavelength IR band in a wavelength range of 8 to 12 μm while objects well above room temperature, such as an operating vehicle engine can be more readily detected in the middle wavelength IR band in a wavelength range of 2 to 5 μm. Accordingly, only detecting a narrow range of the IR spectrum can result in sub-optimal object detection. A radiation detection system capable of accurately imaging across a broad range of wavelengths in an inexpensive manner with low processing latency is desired.